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package model.expr;

public abstract class GeneralExpr
    extends Expr {

    protected String operator;
    protected ExprList subexprs;

    public GeneralExpr(String op) { // *** s/b protected? ***
        super();
        operator = op;
        subexprs = new ExprList();
    }

    // Specific to GeneralExpr

    public void addSubExpr(Expr e) {
        if (e != null) {
            subexprs.add(e);
            e.setParent(this);
        }
    }

    public String getOperator() {
        return operator;
    }

    public String toString() {
        StringBuilder s = new StringBuilder("(");
        s.append(operator);
        int n = subexprs.size();
        if (n != 0) {
            s.append(" ");
            s.append(Integer.toString(n));
            s.append(" subexpression");
            if (n > 1)
                s.append("s");
        }
        s.append(")");
        return s.toString();
    }

}
